Asthma and Allergies
Learning Objectives
Students will be able to:
- Explain what happens in the airways during an asthma attack
- Identify common asthma triggers, especially air quality-related ones
- Describe how allergies affect the respiratory system
- Connect air quality improvements to asthma management
Asthma By the Numbers
Asthma is the leading chronic disease in children and a top reason for missed school days.
What Is Asthma?
Asthma = A chronic condition where airways are inflamed and hypersensitive to triggers
Normal Airways
- Muscles relaxed
- Airways open wide
- Normal mucus layer
- Air flows freely
Asthma Attack
- Muscles tighten (bronchoconstriction)
- Airways narrow
- Excess mucus production
- Swelling of airway walls
The Three Components of an Asthma Attack
Bronchospasm
Muscles around airways tighten, squeezing airways smaller
Inflammation
Airway walls swell, further narrowing the passage
Mucus
Extra thick mucus clogs already-narrow airways
Result: Wheezing, coughing, chest tightness, shortness of breath. Severe attacks can be life-threatening.
Asthma Triggers
| Category | Common Triggers | Connection to Air Quality |
|---|---|---|
| Air Pollution | PM2.5, ozone, NO2, smoke | Direct trigger |
| Allergens | Dust mites, pollen, pet dander, mold | Airborne particles |
| Irritants | Strong odors, cleaning products, smoke | Indoor air quality |
| Respiratory Infections | Colds, flu, COVID-19 | Related (aerosol transmission) |
| Physical | Exercise, cold air, strong emotions | Indirect |
Air Quality and Asthma: The Evidence
- ER visits increase on high pollution days
- School absences rise with poor air quality
- Medication use increases during pollution events
- Lung function decreases measurably with PM2.5 exposure
- Living near highways = higher asthma rates
Research finding: Every 10 μg/m³ increase in PM2.5 is associated with a 2-3% increase in asthma ER visits.
Allergies and Air Quality
What Are Allergies?
Allergies occur when the immune system overreacts to harmless substances (allergens). The body releases histamine and other chemicals, causing symptoms.
Air Quality Connection
- Many allergens are airborne particles
- Pollution can worsen allergy symptoms
- Climate change extending pollen seasons
- Filtration helps remove allergens
Managing Asthma Through Air Quality
What Helps:
- HEPA air purifiers
- Good ventilation
- Remove carpets if possible
- Control humidity (reduce dust mites, mold)
- No smoking indoors
- Check AQI before outdoor activities
- Stay indoors on high pollution days
- Know your personal triggers
- Have medication readily available
- Create an asthma action plan
Key Takeaway
Asthma is a chronic condition affecting millions of people, especially children. During an attack, airways narrow through muscle tightening, inflammation, and excess mucus. Air pollution (PM2.5, ozone, smoke) is a major asthma trigger, and improving air quality—both indoors and outdoors—can significantly reduce asthma symptoms and attacks.